Banning all jokes is also a mistake. The biggest joke on Reddit was the science subs, where hardcore moderators pretended to be responsible for building an encyclopedia of only true statements. Leave that for Wikipedia or actual publishing. Nobody in their right mind would go to Reddit or Lemmy to search for the absolute truth about rocket science anyway. A forum is a place for discussion and conversations and should contain clueless questions and even jokes.

I don't mind a joke or a good pun as long as it's original and relevant to the context. Some jokes only work well in a serious context. The problem is that they're not original and often forced to fit the context.

Serious and interesting comments also get repeated ad nauseam. This happens because of the size of the userbase. It's "original" to someone. (Please don't link the 10.000 xkcd).

Also the age of the users. There are soo many juveniles on Reddit who still have to learn how to even have a conversation that isn't about arguing or one-upping the previous poster.

Overall, I think people here have a better grasp on what they want from an online community.